The research development of novel photocatalysts is the core issue of photo-driven CO2 conversion into high value-added chemicals or fuels, which should be of important significance for achieving the goal of “carbon peak and carbon neutralization”. In this paper, a series of novel Bi-Y-O photocatalyst systems were synthesized by EDTA-assisted hydrothermal method, and with the change of EDTA amount, the crystal structures of as-prepared samples are variational. BiYO3 crystal is obtained with 0.4 g EDTA addition or without EDTA, while Bi1.46Y0.54O3 and Bi3YO6 crystals are synthesized with 0.8 g and 1.2 g EDTA addition, respectively. The photocatalytic CO2 reduction tests reveal that as-prepared BiYO3 with 0.4 g EDTA addition exhibits the best CO2 photoreduction activity, and CO yield is 18.29 μmol·g-1·h-1. After three cycle tests, CO yield still reaches 17.32 μmol·g-1·h-1, higher obviously than CO yields of other samples. Finally, the characterization analysis results show that the assistance of EDTA could not only regulate the structure morphology of BiYO3, but also broaden the light response and enhance the separation efficiency of photogenerated electron-hole pairs, and consequently improve the photocatalytic CO2 reduction performance. The research in this paper provides basic scientific data for the investigation on novel highly-effective B-Y-O photocatalytic system.